People spend most of their time indoors and mostly in the dwelling. It is therefore important to investigate associations between indoor exposure in dwellings and health. Symptoms that may be related to the indoor environment are sometimes referred to as the "sick building syndrome" (SBS). SBS involves symptoms such as eye, skin and upper airway irritation, headache and fatigue. Three longitudinal studies and one prevalence study on personal and environmental risk factors for SBS in adults were performed. The prevalence study included measurements of indoor exposures in the dwellings. The longitudinal studies, with 8-10 years follow-up time, showed that smoking and indoor paint emissions were risk factors for SBS. Moreover, building dampness and moulds in dwellings were risk factors for onset (incidence) of general symptoms, skin symptoms and mucosal symptoms. In addition subjects living in damp dwellings have a lower remission of general symptoms and skin symptoms. Hay fever was a risk factor for onset of skin symptoms and mucosal symptoms, and asthma was a risk factor for onset of general and mucosal symptoms. Biomarkers of allergy and inflammation (bronchial reactivity, total IgE, ECP and eosinophil count) were predictors of onset of SBS symptoms, in particular mucosal symptoms. In the prevalence study, any SBS-symptom was associated with some individual volatile organic compounds of possible microbial origin (MVOC) e.g. 2-pentanol, 2-hexanon, 2-pentylfuran and 1-octen-3ol. Moreover, there were associations between indoor levels of formaldehyde and the plasticizer Texanol and any SBS. The result from the study indicates that individual MVOC are better indicators of SBS than the total value of MVOC. A final conclusion is that smoking, dampness and moulds and emissions from indoor painting may increase the onset of SBS. The indoor environment in dwellings over time has improved, but there is still a need for further improvements of the indoor environment in dwellings. More longitudinal SBS studies are needed.

There is concern about the indoor environment in aircraft but few stud-ies exist on self-rated health (SRH) and respiratory symptoms among pilots. Occupational and non-occupational risk factors for SRH, respira-tory symptoms and other symptoms among commercial pilots were investigated in this thesis. One cohort study and one prevalence study were performed among pilots in one Scandinavian airline company. Fungal DNA, furry pet allergens and volatile organic compounds of microbial origin (MVOC) were measured on board. Cat (fel d1), dog (Can f1) and horse (Ecu cx) allergens were found in all dust samples and allergen levels were 27-75 times higher in aircraft with textile seats as compared to leather surfaces. The sum of MVOCs in the cabin air was 3.7 times higher than in homes in Uppsala and 2-methyl-1-butanol and 3-methyl-1-butanol concentrations were 15-17 times higher. Asper-gillus/Penicillium DNA and Aspergillus versicolor DNA were more common in aircraft with textile seats. One fifth reported SRH as poor or fair, 62% had fatigue, 46% overweight/obesity and 71% insomnia. Poor or fair SRH was associated with overweight/obesity, lack of exercise, insomnia, low sense of coherence (SOC) and high work demand. Re-covery from work was worse among those with insomnia and low social support at work. Fatigue was more common among young or female pilots and related to insomnia and high work demand. Pilots flying MD80 or Saab 2000 aircraft had less fatigue. Pilots exposed to environmental tobacco (ETS) on board had more eye symptoms and fatigue which were reduced after the ban of smoking (in 1997). Pilots with increased work demand developed more rhinitis, dermal symptoms and fartigue and those with decreased work control developed more eye symptoms. The incidence of doctors’ diagnosed asthma and atopy were 2.4 and 16.6 per 1000 person years, respectively. Pilots changing type of flight got more airway infections. Those reporting decreased work control had a higher incidence of atopy. Risk factors in the home environment included ETS, dampness or mould, window pane condensation in winter and living in houses built after 1975. In conclusion, SRH and respiratory health among pilots are associated with specific occupational and non-occupational risk factors.